721441 has 8 divisors (see below), whose sum is σ = 860544. Its totient is φ = 591360.

The previous prime is 721439. The next prime is 721451. The reversal of 721441 is 144127.

721441 = 110² + 111² + ... + 151².

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721441 - 2¹ = 721439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2080 + ... + 2401.

It is an arithmetic number, because the mean of its divisors is an integer number (107568).

2⁷²¹⁴⁴¹ is an apocalyptic number.

It is an amenable number.

721441 is a deficient number, since it is larger than the sum of its proper divisors (139103).

721441 is a wasteful number, since it uses less digits than its factorization.

721441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4511.

The product of its digits is 224, while the sum is 19.

The square root of 721441 is about 849.3768303880. The cubic root of 721441 is about 89.6878486432.

Adding to 721441 its reverse (144127), we get a palindrome (865568).

The spelling of 721441 in words is "seven hundred twenty-one thousand, four hundred forty-one", and thus it is an iban number.